Power supply management apparatus and method thereof

ABSTRACT

An apparatus comprising an onboard energy storage device, an onboard power conversion device configured to be electrically coupled to an external power source for receiving electrical power therefrom, and at least one drive system electrically coupled to the onboard energy storage device and the onboard power conversion device, wherein the onboard energy storage device and the onboard power conversion device cooperatively provide electrical power for the at least one drive system. A vehicle and a method for managing power supply are also disclosed.

BACKGROUND OF THE INVENTION

Embodiments of the disclosure relate generally to improved power supplymechanisms for apparatuses and methods for managing power supplythereof.

Vehicles are mobile machines that are designed and used for transportingpassengers and/or cargos from one place to another. Examples of thevehicles may include bicycles, cars, trucks, locomotives, tractors,buses, boats, and aircrafts. Traditionally, at least some of thesevehicles are powered by engines such as internal combustion engines. Theinternal combustion engines may operate by burning fuels such asdiesels, gasoline, and natural gas for providing necessary power so asto drive motion of the vehicles. However, with rising concerns ofscarcity, cost, and negative environmental impact in association withthe use of the diesels, gasoline, and natural gas, growing interestshave been raised to develop electric powered vehicles such as fully/pureelectric vehicles, hybrid electric vehicles (e.g., integration of abattery and internal combustion engine), and plug-in hybrid electricvehicles. However, wide adoption of the electric powered vehicles islimited by a list of factors, one of which is that onboard or built-inenergy storage device such as battery fails to meet the mileagerequirement.

Therefore, it is desirable to provide improved apparatuses and methodsto address one or more of the above-mentioned limitations.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with an aspect of the present disclosure, an apparatus isprovided. The apparatus comprises an onboard energy storage device, anonboard power conversion device, and at least one drive system. Theonboard power conversion device is configured to be electrically coupledto an external power source for receiving electrical power therefrom.The at least one drive system is electrically coupled to the onboardenergy storage device and the onboard power conversion device. Theonboard energy storage device and the onboard power conversion devicecooperatively provide electrical power for the at least one drivesystem.

In accordance with an aspect of the present disclosure, a vehicle isprovided. The vehicle comprises an onboard energy storage device forproviding a first Direct Current (DC) power; an AlternatingCurrent-Direct Current (AC-DC) converter configured to be electricallycoupled to a utility power grid for receiving input Alternating Current(AC) power from the utility power grid and converting the input AC powerto provide a second DC power; a DC bus electrically coupled to theonboard energy storage device and the AC-DC converter for receiving thefirst DC power and the second DC power respectively; a traction inverterelectrically coupled to the DC bus for converting at least one of thefirst DC power and the second DC power received at the DC bus totraction AC power; and a traction motor electrically coupled to thetraction inverter, the traction motor configured to convert the tractionAC power received from the traction inverter to mechanical power todrive movement of the vehicle, wherein the AC-DC converter continuesreceiving the input AC power from the utility power grid to maintain themovement of the vehicle.

In accordance with an aspect of the present disclosure, a method ofmanaging power supply of an apparatus is provided. The method comprises:receiving input alternating current (AC) power from a utility powergrid; converting the received input AC power to provide a first DCpower; and converting at least part of the first DC power to at leastone of a traction AC power and a power take-off (PTO) AC power,respectively, for a traction motor and a PTO motor of the apparatus;wherein receiving input AC power from a utility power grid isimplemented concurrently with converting at least part of the first DCpower to at least one of a traction AC power and a PTO AC power.

In accordance with an aspect of the present disclosure, acomputer-readable storage medium is provided. The computer-readablestorage medium has a plurality of instructions stored thereon. Theplurality of instructions can be executed by one or more processors toachieve the following: receiving input alternating current (AC) powerfrom a utility power grid; converting the received input AC power toprovide a first DC power; and converting at least part of the first DCpower to at least one of a fraction AC power and a power take-off (PTO)AC power, respectively, for a traction motor and a PTO motor of theapparatus; wherein receiving input AC power from a utility power grid isimplemented concurrently with converting at least part of the first DCpower to at least one of a traction AC power and a PTO AC power.

DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall block diagram of a vehicle in accordance with anexemplary embodiment of the present disclosure;

FIG. 2 is a detailed block diagram of a vehicle in accordance with anexemplary embodiment of the present disclosure;

FIG. 3 is a detailed block diagram of a vehicle in accordance with anexemplary embodiment of the present disclosure;

FIG. 4 is a detailed block diagram of a vehicle in accordance with anexemplary embodiment of the present disclosure;

FIG. 5 is a detailed block diagram of a vehicle in accordance with anexemplary embodiment of the present disclosure;

FIG. 6 is a detailed block diagram of a vehicle in accordance with anexemplary embodiment of the present disclosure;

FIG. 7 is a detailed block diagram of a vehicle in accordance with anexemplary embodiment of the present disclosure;

FIG. 8 is a detailed block diagram of a vehicle in accordance with anexemplary embodiment of the present disclosure;

FIG. 9 is a flowchart which outlines an implementation of a method foroperating a vehicle in accordance with an exemplary embodiment of thepresent disclosure;

FIG. 10 is a flowchart which outlines an implementation of a method foroperating a vehicle in accordance with an exemplary embodiment of thepresent disclosure;

FIG. 11 is a flowchart which outlines an implementation of a block 4014shown in FIG. 10 in accordance with an exemplary embodiment of thepresent disclosure;

FIG. 12 is a flowchart which outlines an implementation of a method foroperating a vehicle in accordance with yet an exemplary embodiment ofthe present disclosure; and

FIG. 13 is a flowchart which outlines a detailed implementation of ablock 5004 shown in FIG. 12 in accordance with an exemplary embodimentof the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments disclosed herein generally relate to improved power supplymechanisms for vehicles and method for managing the power supplythereof. More specifically, the present disclosure proposes a new hybridelectrical power supply mechanism, dual electrical power supplymechanism, or electric-electric hybrid power supply mechanism forvehicles. As used herein, the term “hybrid electrical power supplymechanism,” “dual electrical power supply mechanism,” or“electric-electric hybrid power supply mechanism” refers to a powersupply mechanism that, at least in some modes of operation, a vehiclecan be operated with electrical power cooperatively provided from afirst electrical power arrangement and a second electric powerarrangement. In some implementations, the first electrical powerarrangement may comprise an onboard or built-in electrical power source(e.g., onboard energy storage device such as a battery or battery pack)capable of storing electrical power therein and providing electricalpower for maintaining the operation of the vehicle. The secondelectrical power arrangement may comprise an onboard or built-in powerinterface or power conversion device integrated with the vehicle. Theonboard or built-in power interface or power conversion device iscapable of being coupled to an external power source and converting theelectrical power received from an external power source (e.g., a utilitypower grid) to a suitable form for use by the vehicle (e.g., chargingthe onboard energy storage device or driving at least one drive systemin association with the vehicle). As such, when the external powersource is available to the vehicle, the proposed hybrid electrical powersupply mechanism can be implemented to cooperatively provide electricalpower to maintain operations of the vehicle; while when the externalpower source is unavailable, the vehicle can be powered by the onboardenergy storage device.

In some implementations, based on the proposed hybrid electrical powersupply mechanism, dual electrical power supply mechanism, orelectric-electric hybrid power supply mechanism, the vehicle can bearranged or programmed to operate in a plurality of modes. One of theoperation modes is separate operation control which refers to the firstelectrical power arrangement and the second electrical power arrangementare operating separately for supplying electrical power to the vehicle.More particularly, for the separate operation control, when the secondelectrical power arrangement is available, the first electrical powerarrangement is disabled and the second electrical power arrangement isresponsible for supplying electrical power to maintain the operation ofthe vehicle; while when the second electrical power arrangement is notavailable, the first electrical power arrangement is enabled to supplyelectrical power to maintain the operation of the vehicle. Anotheroperation mode of the vehicle is series hybrid operation control whichrefers to the first electrical power arrangement and the secondelectrical power arrangement simultaneously supply electrical power toat least one drive system of the vehicle. Yet another operation mode ofthe vehicle is combined charging and operation control which refers tothe second electrical power arrangement can be configured tosimultaneously supply electrical power to the first electrical powerarrangement (e.g., charging a battery or battery pack) and at least onedrive system in association with the vehicle. A wide range of vehiclescan benefit from the hybrid electrical power supply mechanism as well asthe various modes of operation proposed herein. Non-limiting examples ofthe vehicles may include land vehicles that drive against ground, suchas bicycles, motorcycles, cars, trucks, vans, buses, tractors, off-wayvehicles, agricultural tractors, E-buses, golf cars, industrialconstruction machines, trailers, locomotives, trains, and subways, toname just a few. The vehicles may also include water vehicles or marinevessels, such as ships, boats, and the like, to name just a few.Furthermore, the vehicles may include air vehicles such as aircrafts,planes, and the like.

The present disclosure can achieve various technical effects ortechnical advantages, one of which is that the mileage of the vehiclecan be extended in at least some modes of operation. For example, in theseries hybrid operation control mode, the onboard power source such asan onboard battery can be charged during the drive system is beingsupplied with electrical power from the onboard power interface. In someembodiments, a conventional internal combustion engine (ICE) may beremoved from the vehicle of the present disclosure. Implementing thevehicle without the use of ICEs may not only contribute to a reductionof tailpipe pollutants, but also help to reduce or eliminate noiseemissions. Other technical effects or technical advantages will becomeapparent to those skilled in the art by referring to the detaileddescriptions provided herein and the accompanying drawings.

In an effort to provide a concise description of these embodiments, notall features of an actual implementation are described in the one ormore specific embodiments. It should be appreciated that in thedevelopment of any such actual implementation, as in any engineering ordesign project, numerous implementation-specific decisions must be madeto achieve the developers' specific goals, such as compliance withsystem-related and business-related constraints, which may vary from oneimplementation to another. Moreover, it should be appreciated that sucha development effort might be complex and time consuming, but wouldnevertheless be a routine undertaking of design, fabrication, andmanufacture for those of ordinary skill having the benefit of thisdisclosure.

Unless defined otherwise, technical and scientific terms used hereinhave the same meaning as is commonly understood by one of ordinary skillin the art to which this disclosure belongs. The terms “first,”“second,” and the like, as used herein do not denote any order,quantity, or importance, but rather are used to distinguish one elementfrom another. Also, the terms “a” and “an” do not denote a limitation ofquantity, but rather denote the presence of at least one of thereferenced items. The term “or” is meant to be inclusive and mean eitherany, several, or all of the listed items. The use of “including,”“comprising,” or “having” and variations thereof herein are meant toencompass the items listed thereafter and equivalents thereof as well asadditional items. The terms “connected” and “coupled” are not restrictedto physical or mechanical connections or couplings, and can includeelectrical connections or couplings, whether direct or indirect. Theterms “circuit,” “circuitry,” and “controller” may include either asingle component or a plurality of components, which are either activeand/or passive components and may be optionally connected or otherwisecoupled together to provide the described function.

Turning now to the drawings, first referring to FIG. 1, in which thereis shown an overall block diagram of a vehicle 10 in accordance with oneexemplary embodiment of the present disclosure. In general, the vehicle10 is adapted to implement the above-mentioned hybrid electrical powersupply mechanism in a manner that at least two sources of electricalpower are cooperatively provided to maintain the operation of thevehicle 10. As shown in FIG. 1, the vehicle 10 may include at least onefirst power source or an onboard power source 22 which is configured tosupply a first form of electrical power or internally-suppliedelectrical power 202 with suitable voltage and/or power to facilitatedriving motion of the vehicle 10 and/or to facilitate performing somespecific tasks in association with the vehicle 10. Depending on thespecific types of vehicle 10, the specific tasks performed by thevehicle 10 may include mowing plants, plowing ground, lifting materials,shoveling materials, excavating materials, and dumping materials, and soon. In one embodiment, the onboard power source 22 may be an onboardenergy storage device such as a battery or battery pack consisting ofmultiple battery cells coupled together in series and/or parallelconfiguration. Non-limiting examples of the battery or battery pack mayinclude lead acid batteries, nickel cadmium batteries (NiCd), nickelmetal hydride batteries (NiMH), lithium ion batteries, lithium polymerbatteries, and so on. In some embodiments, the battery-type onboardenergy storage device 22 may be physically replaced with a new fullycharged one, if the battery power is depleted. Also, a person skilled inthe art will recognize that a variety of energy storage components, suchas ultra-capacitor, fly-wheel, and any other components capable ofstoring electrical energy can be additionally or alternatively used inassociation with the vehicle 10.

With continued reference to FIG. 1, the vehicle 10 also includes anonboard power interface 16 which functions as a power interface betweenvarious components of the vehicle 10 and an external power source 12.The onboard power interface 16 is configured to provide a second sourceof electrical power to maintain operation of the vehicle 10. In oneembodiment, the onboard power interface 16 is electrically coupled tothe external power source 12 via an electrical link 14. In oneembodiment, the electrical link 14 between the external power source 12and the onboard power interface 16 may be one or more electric wires orelectric cables. In other embodiments, the electrical link 14 may bewireless electrical power transfer link. In some specific embodiments,the electrical link 14 between the onboard power interface 16 and theexternal power source 12 is arranged to be flexible. For example, insome applications, an electrical wire of the electrical link 14 isarranged to have sufficient length to allow the onboard power interface16 to continue receiving electrical power while the drive system 30 isoperating to drive motion of the vehicle 10 or perform one or morespecific tasks in association with the vehicle 10. In one embodiment,the onboard power interface 16 may be an onboard power conversion devicewhich is configured to perform power conversion with respect to theelectrical power received from the external power source 12 and provideconverted electrical power with suitable voltage and/or power to variouscomponents of the vehicle 10. Depending on the various operation modesof the vehicle 10 which will be described in more detail below, theelectrical power provided from the onboard power interface 16 can bedelivered to charge the onboard energy storage source 22, or deliveredto a drive system 30 for driving motion of the vehicle 10 or performingone or more specific tasks (e.g., mowing grass, plowing ground, liftingmaterials, shoveling materials, excavating materials, and dumpingmaterials) in association with the vehicle 10.

With continued reference to FIG. 1, the vehicle 10 may further include afirst switch 24. The first switch 24 is electrically coupled to theonboard power source 22 and a bus structure 18. The bus structure 18 maybe any suitable arrangements such as DC bus for facilitatingunidirectional or bidirectional energy transfer between variouscomponents of the vehicle 10. For example, the bus structure 18 mayreceive input such as DC electrical power provided from the onboardpower interface 16. The bus structure 18 may also provide output such asat least a part of the DC electrical power to charge the onboard powersource 22. The first switch 24 can be any type of mechanical and/orelectrical devices or combinations thereof. The first switch 24 can beclosed to establish or form a power/energy transfer link between theonboard power source 22 and the bus structure 18, such that chargingand/or discharging of the onboard power source 22 can be realized. Asused herein, “closed” may refer to an “ON” status of a switch that lowimpedance is created by operating the switch. The first switch 24 canalso be opened to terminate or cut off the power/energy transfer linkbetween the onboard power source 22 and the bus structure 18, such thatthe onboard power source 22 may not be able to supply electrical powerto other vehicle components or the onboard power source 22 can beprotected from over-charging or over-discharging problems. As usedherein, “opened” may refer to an “OFF” status of a switch that highimpedance is created by operating the switch. In one embodiment, theopening and closing of the first switch 24 can be manually performed byan operator or a user such as a driver according to real-time operatingconditions and/or requirements of the vehicle 10. In other embodiments,the first switch 24 can be automatically switched according to on/offsignals which may be generated by monitoring various operatingconditions and/or statuses of the vehicle 10.

With continued reference to FIG. 1, the vehicle 10 may further include asecond switch 26. The second switch 26 is electrically coupled to thebus structure 18 and a drive system 30. The second switch 26 can be anytype of mechanical and/or electrical devices or combinations thereof.Similar to the first switch 24 discussed above, the second switch 26 canalso be manually switched or automatically switched to establish orterminate a power/energy transfer link between the bus structure 18 andthe drive system 30, such that unidirectional or bidirectional powertransfer between the bus structure 18 and the drive system 30 can beenabled or disabled. In one embodiment, as shown in FIG. 1, the drivesystem 30 may include a converter 28 and a motor 34. The converter 28 isone type of a power conversion device functioning to convert one form ofelectrical power to another. For example, the converter 28 may be aDC-AC power conversion device configured to convert DC power receivedfrom a DC bus of the bus structure 18 to AC power. The AC power (e.g.,three-phase AC power) is supplied to the motor 34 (e.g., three-phase ACmotor) such that the motor 34 can be operated to provide a mechanicaloutput such as torque output to drive the vehicle 10 to move. In otherembodiments, the motor 34 can also provide mechanical outputs for one ormore implements or tools designed to perform specific tasks.

With continued reference to FIG. 1, the vehicle 10 can be configured orprogrammed to provide a plurality of modes of operation. Switchingbetween the operation modes of the vehicle 10 may be implementedaccording to instructions/commands input from an operator or a user suchas a driver. In some alternative embodiments, it is possible that in anunmanned vehicle 10, switching or transition between the operation modescan be automatically performed according to operation conditions and/orstatuses of the vehicle 10.

In a first aspect, the vehicle 10 may be configured to provide a firstoperation mode of separate control. In the separate control operationmode, the vehicle 10 can be further configured to operate in differentstates depending on for example whether the external power source 12 isavailable for supplying electrical power to the vehicle 10.

In a first condition, the external power source 12 may be unavailable tothe vehicle 10, that is, the onboard power interface 16 is electricallydecoupled with the external power source 12. In this condition, upondetermining that the onboard power source 22 has sufficient remainingpower stored therein, the onboard power source 22 can be operated toprovide electrical power to various components of the vehicle 10, whichmay be referred to as battery powered mode. In one embodiment, to enablethe power transfer, the first switch 24 and the second switch 26 areclosed or turned on to allow the electrical power obtained from abattery or battery pack of the onboard power source 22 to be transferredto the bus structure 18. In one embodiment, the converter 28 receiveselectrical power at the bus structure 18 and converts the electricalpower to a suitable form of the motor 34 to operate. As a result, themotor 34 can provide necessary mechanical outputs for driving motion ofthe vehicle 10 or performing specific tasks in association with thevehicle 10.

In a second condition, the external power source 12 is available to thevehicle 10 and the onboard power interface 16 can be electricallycoupled to the external power source 12 to receive electrical powertherefrom. The onboard power interface 16 can provide electrical powerto various components of the vehicle 10, which may be referred to asplugin mode. In the plugin mode, when the onboard power source 22 suchas a battery or battery pack is determined to have insufficientremaining power, the first switch 24 can be closed or turned on and thesecond switch 26 can be opened or turned off. That is, the powertransfer link between the bus structure 18 and the drive system 30 iscut off to disable the operation of the drive system 30, while the powertransfer link between the bus structure 18 and the onboard power source22 is established to allow electrical power to be delivered through thepower transfer link to charge the battery or battery pack of the onboardpower source 22. Still in the plugin mode, when it is determined thatthe onboard power source 22 has sufficient remaining power, the onboardpower interface 30 can provide electrical power to other components ofthe vehicle 10. For example, the first switch 24 can be opened and thesecond switch 26 can be closed. That is, the power transfer link betweenthe onboard power source 22 and the bus structure 18 is cut off to makethe onboard power source 22 standby, while the power transfer linkbetween the bus structure 18 and the drive system 30 is established toallow the electrical power obtained from the onboard power interface 16to be transferred to the drive system 30. Consequently, the drive system30 can provide mechanical outputs for driving motion of the vehicle 10or performing specific tasks in association with the vehicle 10.

In a second aspect, the vehicle 10 may be configured to provide a secondoperation mode of series hybrid control. In the series hybrid controlmode, upon determining that the external power source 12 is available,the onboard power interface 16 can be electrically coupled to theexternal power source 12 to receive electrical power therefrom andprovide converted electrical power to the bus structure 18. If theonboard power source 22 such as a battery or battery pack is determinedto have insufficient remaining power (e.g., a SOC of the battery orbattery pack is below than a first threshold value, e.g., 10%), thefirst switch 24 is closed and the second switch 26 is opened. That is,the energy transfer link between the onboard power source 22 and the busstructure 18 is established to allow electrical power to be deliveredthrough the energy transfer link for charging the battery or batterypack of the onboard power source 22. The energy transfer link betweenthe bus structure 18 and the drive system 30 is cut off to disable theoperation of the drive system 30. Still in the series hybrid controlmode, if the onboard power source 22 such as a battery or battery packis determined to have sufficient remaining power (e.g., a SOC of thebattery or battery pack is above a second threshold value, e.g., 80%),both the first switch 24 and the second switch 26 are closed or turnedon. In this case, the onboard power source 22 and the onboard powerinterface 16 can be paralleled to provide electrical power to the drivesystem 30, as such, the drive system 30 can be operated to drive motionof the vehicle 10 and/or perform specific tasks in association with thevehicle 10. In some embodiments, the amount of the electrical powerprovided from the onboard power source 22 and the amount of theelectrical power provided from the onboard power interface 16 can bedetermined according to some predetermined distribution rules. Forexample, in one embodiment, the onboard power interface 16 is controlledto provide average power for the drive system 30, while the onboardpower source 22 is controlled to provide dynamic power for the drivesystem 30. That is, when a traction motor of the drive system 30requires large mechanical torque to accelerate the vehicle 10 or animplement or tool of the vehicle 10 requires large torque to performspecial tasks, the onboard power source 22 can be configured to providepeak power to meet this requirement. When the traction motor of thedrive system 30 doesn't require large mechanical torque or the implementor tool of the vehicle 10 is operating with light load, the onboardpower source 22 can reduce its electrical power output. In a specificembodiment, the onboard power interface 16 may be controlled to operateat a constant output voltage mode, thus design of the onboard powerinterface 16 can be simplified.

In a third aspect, the vehicle 10 may be configured to provide a thirdoperation mode of combined charging and operation control. In thecombined charging and operation control mode, charging of the onboardpower source 22 and driving of the drive system 30 can be performedconcurrently or simultaneously. More specifically, when the externalpower source 12 is available, the onboard power interface 16 can beelectrically coupled to the external power source 12 to receive theelectrical power therefrom and convert the received electrical power toa suitable form for the bus structure 18. In one embodiment, both thefirst switch 24 and the second switch 26 can be closed or turned on.That is, a first energy transfer link between the onboard power source22 and the bus structure 18 can be established to allow at least a partof the electrical power at the bus structure 18 to be delivered throughthe first energy transfer link for charging a battery or a battery packof the onboard power source 22. Also, a second energy transfer linkbetween the bus structure 18 and the drive system 30 can be establishedto allow at least part of the electrical power at the bus structure 18to be delivered through the second energy transfer link for drivingmotion of the vehicle 10 and/or performing one or more specific tasks inassociation with the vehicle 10. In a specific embodiment, the onboardpower interface 16 is controlled to operate at a constant current mode.In one embodiment, in the constant current mode, a current reference forcharging a battery or battery back of the onboard power source 22 can bedetermined based at least in part on a desired power of the drive system30 and a desired charging power of the onboard power source 22. Still inthe combined charging and operation control mode, when it is determinedthat a battery or battery pack of the onboard power source 22 is chargedto have sufficient remaining power (e.g., a SOC of the battery orbattery exceeding a high-SOC threshold value, e.g., 80%), the onboardpower interface 16 and the onboard power source 22 can be paralleled toprovide electrical power to the drive system 30, as such, the drivesystem 30 can drive motion of the vehicle 10 and/or perform one or morespecific tasks in association with the vehicle 10.

FIG. 2 illustrates a detailed block diagram of a vehicle 100 inaccordance another exemplary embodiment of the present disclosure. Asshown in FIG. 2, the vehicle 100 includes an onboard energy storagedevice 102 which may be a battery or battery back with suitable currentand/or power output. The onboard energy storage device 102 iselectrically coupled to an ES switch 104 which can be switched on andoff according to switching signals 166 transmitted from a vehiclecontroller 152. In alternative embodiments, the ES switch 104 can bemanually switched on and off by an operator. The vehicle 100 furtherincludes an onboard power conversion device 136 which may beelectrically coupled to a utility power grid 132. In one embodiment,when the utility power grid 132 is available for supplying electricalpower, the utility power grid 132 may provide AC electrical power 134(e.g., 220V or 380V electrical power depending on local grid standard)to the onboard power conversion device 136. In one embodiment, theonboard power conversion device 136 may include an AC-to-DC conversiondevice (e.g., rectifier) which is configured for converting the ACelectrical power 134 according to control signals 162 transmitted fromthe vehicle controller 152 and provide DC electrical power with suitablevoltage and/or power. The DC electrical power is supplied to a DC bus122 for further delivery to various components of the vehicle 100.

With continued reference to FIG. 2, the vehicle 100 further include adrive system 30 which can be supplied with electrical power from theonboard energy storage device 102 and/or the onboard power conversiondevice 136. In one embodiment, the drive system 30 may include atraction drive system or TM branch as indicated by reference numeral 124in FIG. 1. The fraction drive system or the TM branch 124 is arrangedfor providing necessary mechanical output for driving motion of thevehicle 100. In one embodiment, the TM branch 124 includes a TM switch108, a TM bus 112, a TM converter 114, and a fraction motor 118. The TMswitch 108 is electrically coupled between the DC bus 122 and the TM bus112. In one embodiment, the TM switch 108 can be opened or closedaccording to switching signals 164 transmitted from the vehiclecontroller 152, such that energy/power transfer link between the DC bus122 and the TM branch 124 can be established or terminated. The energyflow between the DC bus 122 and the TM branch 124 can be unidirectionalor bidirectional.

The TM converter 114 is electrically coupled between the TM bus 112 andthe traction motor 118. The TM converter 114 is configured to performpower conversion by converting DC electrical power received from the TMbus 112 to an output power 116 with suitable form for use by thetraction motor 118. In one embodiment, the TM converter 114 may comprisean inverter such as a DC-AC inverter which is capable of converting theDC electrical power at the TM bus 112 to AC electrical power 116 (e.g.,three-phase AC electrical power). The AC electrical power 116 can beregulated by a vehicle controller 152. For example, in one embodiment,in response to a traction torque command signal generated by operatingan input device such as an acceleration pedal, the vehicle controller152 can send control signals 154 to the TM converter 114 to cause the TMconverter 114 to provide regulated AC electrical power 116 for thetraction motor 118. As such, the fraction motor 118 (e.g., AC electricmotor) can operate according to the AC electrical power 116 to providedesired torque output for driving motion of the vehicle 100. In otherembodiments, the traction motor 118 may include a DC motor andcorrespondingly the TM converter 114 may comprise a DC-DC converter toperform DC power conversion. The vehicle controller 152 may include anysuitable programmable circuits or devices such as a digital signalprocessor (DSP), a field programmable gate array (FPGA), a programmablelogic controller (PLC), and an application specific integrated circuit(ASIC).

With continued reference to FIG. 2, the drive system 30 may furtherinclude a power take-off (PTO) drive system or a PTO branch as indicatedby reference numeral 126 in FIG. 2. For purpose of illustration anddescription, only a single PTO branch 124 is shown and described herein,however, a person having ordinary skill in the art will recognize thatin some alternative embodiments, the drive system 30 may include aplurality of PTO branches which may be configured in parallel with eachother. The PTO drive system or the PTO branch 126 is arranged forproviding necessary mechanical power output for example torque output,for performing one or more specific tasks in association with thevehicle 100. Examples of the specific tasks may include mowing plants,plowing grounds, lifting materials, shoveling materials, excavatingmaterials, and dumping materials. In one embodiment, the PTO drivesystem or the PTO branch 126 may include a PTO switch 138, a PTO bus142, a PTO converter 144, and a PTO motor 148. The PTO switch 138 iselectrically coupled between the DC bus 122 and the PTO bus 142. The PTOswitch 138 can be switched on or off according to PTO switching signals162 transmitted from the vehicle controller 152, such that anenergy/power transfer link between the DC bus 122 and the PTO branch 126can be established or terminated. The energy flow between the DC bus 122and the PTO branch 126 can be unidirectional and bidirectional.

The PTO converter 144 is electrically coupled between the TM bus 142 andthe PTO motor 148. The PTO converter 144 is configured to perform powerconversion by converting DC electrical power received at PTO bus 142 toa PTO output 146 having a suitable form for use by the PTO motor 148. Inone embodiment, the PTO converter 144 may comprise a PTO DC-AC converteror PTO inverter which is capable of converting DC electrical powerreceived at the PTO bus 142 to AC electrical power 146 (e.g.,three-phase AC electrical power). Also, the AC electrical power 146 canbe regulated by the vehicle controller 152. For example, in oneembodiment, in response to a PTO torque command signal generated byoperating an input device installed with the vehicle 100, the vehiclecontroller 152 can send control signals 156 to the PTO converter 144 tocause the PTO converter 144 to provide regulated AC electrical power 146for the PTO motor 148. As such, the PTO motor 148 can operate accordingto the AC electrical power 146 to provide desired torque output forperforming one or more specific tasks in association with the vehicle100. In other embodiments, the PTO motor 148 may include a DC motor andcorrespondingly the PTO converter 144 may comprise a DC-DC converter toperform DC power conversion. In some applications, for example, in aforklift apparatus, the PTO motor 148 may be associated with one or morehydraulic pump systems for performing the tasks of lifting andtransporting materials/cargoes.

The vehicle 100 shown in FIG. 2 can be configured or programmed tooperate with a plurality of modes, such as separate control mode, serieshybrid control mode, and combined charging and operation mode. Detaileddescription of these operations mode will be described later withreference to flow chart diagram of FIGS. 9-13. Before describing theflow chart diagrams, various structural embodiments of the vehicle aredescribed with reference to FIGS. 3-8.

FIG. 3 illustrates a detailed block diagram of a vehicle 110 inaccordance with another exemplary embodiment of the present disclosure.The overall structure of the vehicle 110 and the operation thereof issubstantially similar to the vehicle 100 that has been described withreference to FIG. 2. One of the differences of the vehicle 110 shown inFIG. 3 is that the onboard power conversion device 137 is electricallycoupled to a portable electricity generator 133. The portableelectricity generator 133 may run on diesel fuel, gasoline, or othersuitable material. When the portable electricity generator 133 isavailable, the onboard power conversion device 137 can be electricallycoupled to the portable electricity generator 133 and receive theelectrical power 135 (e.g., AC electrical power) from the portableelectricity generator 133 and convert the received electrical power 135to suitable form for use by various components of the vehicle 110. Inone embodiment, the onboard power conversion system 137 may comprise anAC-DC conversion device which is capable of converting AC electricalpower 135 to DC electrical power supplied to a DC bus 122. Theelectrical power output from the onboard power conversion device 137 canbe regulated according to control signals 163 transmitted from thevehicle controller 152. The vehicle 110 shown in FIG. 3 can also beconfigured to operate with a plurality of modes, such as separationcontrol mode, series hybrid control mode, and combined charging andoperation control mode, which will be described in more detail belowwith reference to the flow chart diagrams of FIGS. 9-13.

FIG. 4 illustrates a detailed block diagram of a vehicle 120 inaccordance with another exemplary embodiment of the present disclosure.The overall structure of the vehicle 120 shown in FIG. 4 and theoperations thereof is substantially similar to the vehicle 100 shown anddescribed with reference to FIG. 2. One of the differences of thevehicle 120 shown in FIG. 4 is that an onboard power conversion device176 is electrically coupled to a solar panel device 172. The solar paneldevice 172 is one type of a renewable power generation device which isdesigned for converting solar or light irradiation energy intoelectrical energy for direct consumption by household or transmissionand distribution by a power grid. In some embodiments, the solar paneldevice 172 is arranged as a standalone device which is located separatewith respect to the vehicle 120. In some other embodiments, the solarpanel device 172 may be integrated with the vehicle 120. As such, whenthe solar panel device 172 is available to provide electrical powerconverted from solar irradiation, the onboard power conversion device176 can be configured to receive electrical power 174 provided from thesolar panel device 172 and convert the electrical power 174 to anelectrical power with suitable voltage and/or power for delivering tovarious components of the vehicle 120. In one embodiment, the onboardpower conversion device 176 may include a DC-DC converter which isconfigured to perform DC-DC power conversion to provide DC electricalpower with suitable voltage and/or power. Also, the DC electrical powerprovided from the DC-DC converter 176 can be regulated according tocontrol signals 165 transmitted from the vehicle controller 152. Thevehicle 120 shown in FIG. 4 can also be configured to operate with aplurality of modes, such as separation control mode, series hybridcontrol mode, and combined charging and operation control mode, whichwill be described in more detail below with reference to the flow chartdiagrams of FIGS. 9-13.

FIG. 5 illustrates a detailed block diagram of a vehicle 140 inaccordance with another exemplary embodiment of the present disclosure.The overall structure of the vehicle 140 shown in FIG. 5 and theoperations thereof are substantially similar to the vehicle 100 shownand described with reference to FIG. 2. One of the differences of thevehicle 140 shown in FIG. 5 is that the onboard power conversion device186 can be electrically coupled to a wind turbine generator 182. A windturbine generator 182 is another form of renewable power generationdevice that is designed for converting kinetic energy of wind intoelectrical energy for grid transmission and/or distribution. In someembodiments, multiple wind turbine generators 182 may be groupedtogether as a wind farm for providing greater power output. In oneembodiment, one or more wind turbine generators 182 may be integratedwith the vehicle 140. In other embodiments, one or more wind turbinegenerators 182 may be separately arranged with respect to the vehicle140. In one embodiment, when the wind turbine generator 182 is availableto provide electrical power converted from wind energy, the onboardpower conversion device 186 can be electrically coupled to the windturbine generator 182 and receive the electrical power 184 therefrom. Inone embodiment, the electrical power 184 provided from the wind turbinegenerator 182 may be AC power with suitable voltage and/or power.Correspondingly, the onboard power conversion device 186 may comprise anAC-DC converter functioning to convert the AC electrical power 184 to DCpower with suitable voltage and/or power to be supplied to the DC bus122. In other embodiments, additionally or alternatively, the windturbine generator 182 may be configured to provide DC power withsuitable voltage and/or power 184. Correspondingly, the onboard powerconversion device 186 may additionally or alternatively comprise a DC-DCconverter 186 functioning to convert first DC power 184 to second DCpower with suitable voltage and/or power to be supplied to the DC bus122. The output of the onboard power conversion device 186 can beregulated or adjusted according to control signals 167 transmitted fromthe vehicle controller 152. The vehicle 140 shown in FIG. 5 can also beconfigured to operate with a plurality of modes, such as separationcontrol mode, series hybrid control mode, and combined charging andoperation control mode, which will be described in more detail belowwith reference to the flow chart diagrams of FIGS. 9-13.

FIG. 6 illustrates a detailed block diagram of a vehicle 150 inaccordance with another exemplary embodiment of the present disclosure.The overall structure and detailed operations of the vehicle 150 show inFIG. 6 is substantially similar to what has been described above withreference to FIGS. 1-5. One difference of the vehicle 150 shown in FIG.6 is that the vehicle 150 may be configured to be electrically coupledto a hydro-micro turbine generator 183. The hydro-micro turbinegenerator 183 is yet another form of renewable power generation devicewhich is functioning to convert water wave energy into electrical power.In one embodiment, the hydro-micro turbine generator 183 may beintegrated with the vehicle 150. In other embodiments, the hydro-microturbine generator 183 may be arranged as a standalone device, that is,located remotely with respect to the vehicle 150. As shown in FIG. 6,the vehicle 150 is provided with an onboard power conversion device 187(e.g., a AC-DC converter or a DC-DC converter) for converting electricalpower 185 provided from the hydro-micro turbine generator 185 to DCpower with suitable voltage and/or power to be supplied to the DC bus122. In some embodiments, the DC power output from the onboard powerconversion device 187 can be regulated according to control signals 169transmitted from the vehicle controller 152. The vehicle 150 shown inFIG. 6 can also be configured to operate with a plurality of modes, suchas separation control mode, series hybrid control mode, and combinedcharging and operation control mode, which will be described in moredetail below with reference to the flow chart diagrams of FIGS. 9-13.

FIG. 7 illustrates a detailed block diagram of a vehicle 160 inaccordance with another exemplary embodiment of the present disclosure.The overall structure and detailed operations of the vehicle 160 issubstantially similar to what has been described above with reference toFIGS. 1-6. One difference of the vehicle 160 shown in FIG. 7 is that aconverter 198 is provided in association with the onboard energy storagedevice 102. In the illustrated embodiment, the converter 198 isillustrated being electrically coupled between the ES switch 104 and theDC bus 122. In other embodiments, the converter 198 can also beelectrically coupled between the onboard energy storage device 102 andthe ES switch 104. In one embodiment, the converter 198 may comprise aDC-DC converter which is configured to convert first DC power 103provided from the onboard energy storage device 102 to second DC power105 with suitable voltage and/or power to be supplied to the DC bus 122.In one embodiment, the DC-DC converter 198 may comprise a unidirectionalDC-DC converter for performing DC power conversion, such as boosting thevoltage of the first DC power 103 to match the voltage at the DC bus122. In other embodiments, the DC-DC converter 198 may comprise abidirectional DC-DC converter which may be useful for collecting powerduring regenerative or braking operations of the vehicle 160. Forexample, when the vehicle 160 is operating in a regenerative mode, thebidirectional DC-DC converter 198 can be operated to convert at least apart of the DC power at the DC bus 122 to DC power for charging theonboard energy storage device 102. In the regenerative mode, at leastpart of the DC power at the DC bus 122 can be provided from the TMbranch 124 by operating the traction motor 118 as a generator, whichconverts motion energy of the vehicle 160 into electrical power. The DCpower at the DC bus 122 can also be provided from the PTO branch 126.For example, when vehicle 160 is a forklift, the PTO motor 148 can beoperated as a generator which converts gravitational potential energy ofa load into electrical power. As shown in FIG. 6, the converter 198 canbe operated according to control signals 168 transmitted from thevehicle controller 152 to provide desired DC power for the DC bus 122 ordesired DC power for the onboard energy storage device 102.

With continued reference to FIG. 7, in the illustrated embodiment, theonboard power conversion device 196 is electrically coupled to anexternal power source 192 for receiving electrical power 194 providedtherefrom. The external power source 192 can be any one of the powersources described above with reference to FIGS. 2-5. When the externalpower source 192 is available, electrical power obtained from theexternal power source 192 can be provided to the TM branch 124 and/orthe PTO branch 126 in coordination with the onboard energy storagedevice 102. The vehicle 160 shown in FIG. 7 can also be configured tooperate with a plurality of modes, such as separation control mode,series hybrid control mode, and combined charging and operation controlmode, which will be described in more detail below with reference to theflow chart diagrams of FIGS. 8-10.

FIG. 8 illustrates a detailed block diagram of a vehicle 180 inaccordance with yet another exemplary embodiment of the presentdisclosure. The overall structure and operations thereof aresubstantially similar to what has been described above with reference toFIGS. 1-6. For example, the vehicle 180 can optionally include aunidirectional or bidirectional DC-DC converter 198 electrically coupledbetween the onboard energy storage device 102 and the DC bus 122. Inaddition, the vehicle 180 may be further provided with an onboard energystorage protection function. More specifically, the vehicle 180 mayinclude a sensor 197 which is electrically coupled to the output of theonboard energy storage device 102 for detecting one or more electricalparameters in association with the onboard energy storage device 102. Inone embodiment, as shown in FIG. 7, a current detector is used as thesensor 197 for detecting charging and/or discharging current inassociation with the operation of the onboard energy storage device 102.In other embodiments, other sensors or transducers may be used,including but not limited to, voltage sensors and/or thermal sensors. Inresponse the current detection, the current detector 197 may transmit acurrent feedback signal 199 representing actual or practical currentflowing into or flowing from the onboard energy storage device 102 tothe vehicle controller 152. The vehicle controller 152 may derive acharging and/or discharging status of the onboard energy storage device102 based at least in part on the current feedback signal 197. In oneembodiment, when a state of charge (SOC) of a battery or a battery packof the onboard energy storage device 102 is determined to be fullycharged (e.g., a SOC value exceeding a preset value), the vehiclecontroller 152 may transmit a switching signal 166 to the ES switch 104to open the ES switch 104 (i.e., OFF state) to stop charging the onboardenergy storage device 102. In another situation, when the SOC of abattery of a battery pack of the onboard energy storage device 102 isdetermined to be overly discharged (e.g., a SOC value being smaller thana preset value), the vehicle controller 152 may similarly transmit aswitching signal 166 to the ES switch 104 to stop discharging theonboard energy storage device 102.

It should be noted that the various embodiments of the vehicles 100,110, 120, 140, 150, 160, 180 shown and described above are merelyexamples only to help explain the general principles of the presentdisclosure. In some embodiments, two or more of the vehicles describedabove can be combined in some manner. For example, in some embodiments,the vehicle 100 shown in FIG. 2 can also be configured to have anonboard power conversion device 136 that is capable of receivingelectrical power both from the utility power grid 132 and the solarpanel device 172 shown in FIG. 4. Thus, as long as one of the utilitypower grid 132 and the solar panel device 172 is available, the vehicle100 can be operated with electrical power concurrently provided from theexternal power source (either the utility power grid 132 or the solarpanel device) and the onboard energy storage device 102. Similarly, insome other embodiments, the vehicle 120 shown in FIG. 4 can beconfigured to have an onboard power conversion device 176 that iscapable of receiving electrical power both from the solar panel device172 and the wind turbine generator 182 shown in FIG. 5.

FIGS. 9-13 illustrate flowchart diagrams of methods 3000, 4000, and 5000for operating a vehicle and/or managing power supply of a vehicle inaccordance with exemplary embodiments of the present disclosure. Themethods 3000, 4000, and 5000 described herein can be implemented with atleast some of the vehicles 100, 110, 120, 140, 150, 160, 180 shown inFIGS. 2-8. For purpose of simplifying description of these methods, theone or more blocks of methods 3000, 4000, and 5000 will be specificallydescribed as being tied to one or more components of the vehicle 180shown in FIG. 8, however, the implementation of these method blocksshould not be limited to the one or more components. Also, it should benoted that at least a part of blocks of these methods 3000, 4000, and5000 shown in FIGS. 9-13 may be programmed with software instructionsstored in a computer-readable storage medium which, when executed by aprocessor, perform various blocks of the methods 3000, 4000, and 5000.The computer-readable storage medium may include volatile andnonvolatile, removable and non-removable media implemented in any methodor technology. The computer-readable storage medium includes, but is notlimited to, RAM, ROM, EEPROM, flash memory or other memory technology,CD-ROM, digital versatile disks (DVD) or other optical storage, magneticcassettes, magnetic tape, magnetic disk storage or other magneticstorage devices, or any other non-transitory medium which can be used tostore the desired information and which can accessed by a processor.

Turning now to FIG. 9, the method 3000 generally provides a separatecontrol operation mode for the vehicle 180 to implement. One benefit ofproviding such a separate control operation mode for the vehicle 180 isthat the design of the control system of the vehicle 180 can besimplified. In one embodiment, the method 3000 may start to implementfrom block 3002. At block 3002, an electrical connection or coupling forinterconnecting the vehicle with an external power source isestablished. The electrical connection may be established by pluggingone or more electrical wires or cables to an electric outlet inassociation with the external power source 192. In other embodiments, itis possible to establish a wireless connection between the externalpower source 192 and the vehicle 180 for wireless electrical powertransfer. In one embodiment, the vehicle 180 is particularly equippedwith an onboard power interface such as an onboard power conversiondevice 196 (e.g., AC-DC converter) for converting the electrical power194 (e.g., AC electrical power) received from the external power source192 to a suitable form (e.g., DC electrical power) for variouscomponents of the vehicle 180.

At block 3004, the method 3000 continues to implement by determiningwhether a charging mode of the vehicle is enabled. More specifically,the determining at block 3004 can be made by the vehicle controller 152to ascertain whether a battery or a battery pack of the onboard energystorage device 102 has sufficient remaining power. If the determining bythe vehicle controller 152 reveals that the onboard energy storagedevice 102 has low remaining power, that is, the vehicle 180 should becharged, the method 3000 then proceeds to block 3006 to implement. Onthe other hand, if the determining by the vehicle controller 152 revealsthat a battery or a battery pack of the onboard energy storage device102 has sufficient remaining power, that is, the vehicle 180 doesn'tneed to be charged, the method 3000 may proceed to block 3014 toimplement, which will be described later.

At block 3006, following the affirmative determination at block 3004that the vehicle should be operating in the charging mode, all the drivesystem of the vehicle is disabled. More specifically, in one embodiment,a fraction drive system or a traction branch 124 shown in FIG. 8 fordriving motion of the vehicle 180 is disabled. In another embodiment,additionally, a PTO drive system or a PTO branch 126 shown in FIG. 8 forperforming one or more specific tasks in association with the vehicle180 is disabled. In a particular embodiment, a TM switch 108 in the TMbranch 124 and/or a TPO switch 138 in the PTO branch 126 can be openedor turned off by switching signals 164, 162 transmitted from the vehiclecontroller 152. In other embodiments, the TM switch 108 and the PTOswitch 138 can be opened or turned off in a manual manner.

At block 3008, further following the affirmative determination at block3004 that the vehicle should be operating in the charging mode, themethod 3000 may continue to implement by establishing an energy transferlink between the external power source and the onboard energy storagedevice. In one embodiment, the establishment of the energy transfer linkcan be achieved by closing or turning on the ES switch 104 according toswitching signal 168 transmitted from the vehicle controller 152. Inalternative embodiments, the ES switch 104 can also be closed or turnedon by manual operation of an operator or a user such as a driver.

At block 3012, the method 3000 continues to implement by transferring atleast a part of the electrical energy from the external power source tothe onboard energy storage device. In one embodiment, the electricalpower provided from the external power source 132 is first converted bythe onboard power conversion device 136 such as an AC-DC converter to DCelectrical power. The DC electrical power then is delivered through theDC bus 122 and the ES switch 104 to the onboard energy storage device102, such that the onboard energy storage device can be charged. Variouscharging strategies may be employed for charging the onboard energystorage device 102. For example, the onboard energy storage device maybe charged with a constant current or a constant voltage or acombination thereof.

At block 3014, following the negative determination made at block 3004that the vehicle is not operating in the charging mode, the method 3000may continue to determine whether the vehicle should be operating in adriving mode. The determining may be made by the vehicle controller 152to ascertain whether one or more command signals for driving the vehicle180 has been received. If the determining by the vehicle controller 152reveals that one or more command signals has been received, that is thevehicle 180 should be operating in the driving mode, the method 3000 mayproceed to block 3015 to implement, which will be described later. Onthe other hand, if the determining by the vehicle controller 152 revealsthat there aren't any command signals received by the vehicle 180, thatis, the vehicle 180 is not operating in the driving mode, the method3000 may return back to block 3004 for further determining whether thevehicle 180 should be operating in charging mode.

At block 3015, following the affirmative determination that the vehicleis operating in the driving mode, the method 3000 may continue toimplement by disabling the onboard energy storage device of the vehicle.In one embodiment, the ES switch 104 is turned off or opened accordingto switching signal 166 transmitted from the vehicle controller 152,such that the energy transfer link between the DC bus 122 and theonboard energy storage device 102 is cut off, thereby, the onboardenergy storage device 102 stops charging and/or discharging.

At block 3016, following the affirmative determination that the vehicleis operating in the driving mode, the method 3000 may continue toimplement by establishing at least one energy transfer link between theexternal power source and at least one drive system of the vehicle. Inone embodiment, an energy transfer link is established between theexternal power source 192 and a traction drive system or a TM branch124. More specifically, a TM switch 108 is turned on or closed by aswitching signal 164 transmitted from a vehicle controller 152. Inanother embodiment, the TM switch 108 may be turned on or closed bymanual operation. In another embodiment, additionally or alternatively,another energy transfer link is established between the external powersource 192 and a PTO drive system or a PTO branch 126 shown in FIG. 8.More specifically, the establishment of the another energy transfer linkmay be achieved by turning on or closing the PTO switch 138 according toswitching signal 162 transmitted from the vehicle controller 152. Inalternative embodiment, the PTO switch 138 may be turned on or closed bymanual operation.

At block 3018, with the at least one established energy transfer link,electrical power is transferred from the external power source to the atleast one drive system. In one embodiment, the electrical power providedfrom the external power source is first converted to a suitable form(e.g., DC power) for the DC bus 122 by the onboard power interface orthe onboard power conversion device 136 (e.g., AC-DC converter). Then,the DC electrical power on the DC bus 122 is delivered through theestablished energy transfer link to the TM branch 124 for driving motionof the vehicle 180. In another embodiment, the DC electrical power onthe DC bus 122 can be delivered through the another established energytransfer link to the PTO branch 126 for performing one or more specifictasks in association with the vehicle 180.

As long as the electrical power from the external power source 132 isavailable, the onboard power interface or the onboard power conversiondevice 136 continues supplying electrical power to the DC bus 122 tomaintain the movement of the vehicle 180 or to maintain the one or morespecific tasks implementation in association with the vehicle 180. Thebenefit of using externally-supplied electrical power for driving motionof the vehicle 180 or performing one or more special task in associationwith vehicle 180 is that the power stored in the battery or battery packof the onboard energy storage device 102 can be reserved for extendingthe overall mileage of the vehicle 180. For example, in one embodiment,the vehicle 180 may be embodied as an electric tractor. When an externalpower source such as a utility power grid 132 is available, the electrictractor 180 can be operated with the electrical power 134 provided fromthe utility power grid 132 without consuming the energy stored in thebattery or battery pack of the onboard energy storage device 102. Aftersome tasks such as plowing grounds have been performed, and the externalpower source such as the utility power grid 132 is unavailable forsupplying electrical power to maintain the driving of the vehicle 180,the vehicle 180 can quickly switch to an internal power supply mode anduse electrical power obtained from the onboard energy storage device 102to maintain the operation of the vehicle 180.

Referring to FIG. 10, the method 4000 generally provides a series hybridcontrol operation mode for the vehicle 180 to implement or operate with.The method 4000 contains similar blocks as those have been describedwith reference to FIG. 9. For example, the method 4000 contains a block4002 similar to block 3002 for establishing an electrical connectionbetween the vehicle and an external power source.

At block 4004, the method 4000 continues to implement by determiningwhether an onboard energy storage device has a low remaining power. Inone embodiment, the determining may be made by a vehicle controller 152to ascertain whether a state of charge (SOC) of an battery or batterypack of the onboard energy storage device 102 is equal to or below afirst threshold value (may also be referred to as a low-SOC thresholdvalue). If the determining by the vehicle controller 152 reveals thatthe SOC of the onboard energy storage device is equal to or below thefirst threshold value, that is, the onboard energy storage device 102has low remaining power, the method 4000 may proceed to block 4005 toimplement, which will be described in more detail later. On the otherhand, if the determining by the vehicle controller 152 reveals that theSOC of the onboard energy storage device 102 is not equal to or belowthe first threshold value, the method 4000 may proceed to block 4012 toimplement, which will be described in more detail later.

At block 4005, all the drive system of the vehicle is disabled. In oneembodiment, a traction drive system or a traction branch 124 shown inFIG. 8 for driving motion of the vehicle 180 is disabled. In anotherembodiment, additionally, a PTO drive system or a PTO branch 126 shownin FIG. 8 for performing one or more specific tasks in association withthe vehicle 180 is disabled. In a particular embodiment, a TM switch 108in the TM branch 124 and/or a TPO switch 138 in the PTO branch 126 canbe opened or turned off by switching signals 164, 162 transmitted fromthe vehicle controller 152. In other embodiments, the TM switch 108 andthe PTO switch 138 can be opened or turned off in a manual manner.

At block 4006, following the affirmative determination that the onboardenergy storage device has low remaining power, the method 4000 continuesto implement by establishing an energy transfer link between theexternal power source and the onboard energy storage device. With theestablished energy transfer link, the method 4000 may move to block 4008to implement, where at least a part of the electrical energy providedfrom the external power source is delivered to the onboard energystorage device so as to charge the energy storage device. Blocks 4006,4008 are substantially similar to the blocks 3008 and 3012 that havebeen shown and described with reference to FIG. 9, thus, detaileddescriptions of the two blocks 4006, 4008 are omitted here.

At block 4012, the method 4000 continues to implement by determiningwhether an onboard energy storage device of the vehicle has sufficientremaining power. In one embodiment, the determining at block 4012 may bemade by the vehicle controller 152 to ascertain whether the SOC of abattery or a battery pack of the onboard energy storage device 102 isequal to or above a second threshold value (may also be referred to ashigh-SOC threshold value). If the determination made by the vehiclecontroller 152 reveals that the SOC of the battery or battery pack ofthe onboard energy storage device 102 is equal to or above the secondthreshold value or the high-SOC threshold value, that is, the onboardenergy storage device 102 has sufficient remaining power, the method4000 may proceed to the block 4014 to implement, which will be describedin more detail later. On the other hand, if the determining made by thevehicle controller 152 reveals that the SOC of the battery or batterypack of the onboard energy storage device 102 is not equal to or abovethe second threshold value or the high-SOC threshold value, the method4000 may proceed to block 4016 to implement, which will be described inmore detail later.

At block 4014, the method 4000 continues to implement by providing acombination electrical power from the onboard energy storage device andthe external power source to at least one drive system. Implementationof the block 4014 may involve a plurality of sub-blocks. FIG. 11illustrates a more detailed flowchart diagram of the block 4014 inaccordance with one exemplary embodiment.

Referring to FIG. 11, at sub-block 4022, an energy transfer link betweenthe onboard energy storage device and a DC bus is established. In oneembodiment, the establishment of the energy transfer link may beachieved by turning on or closing the ES switch 104 according toswitching signal 166 transmitted from the vehicle controller 152. Atsub-block 4024, with the established energy transfer link, electricalpower is transferred from the onboard energy storage device 102 to theDC bus 122.

Sub-block 4032 may be implemented concurrently with the sub-block 4024.At sub-block 4032, at least part of electrical power is transferred fromthe external power source to the DC bus. In one embodiment, as shown inFIG. 8, an onboard power conversion device 196 is utilized forconverting electrical power provided from the external power source 192to DC electrical power, which in turn is supplied to the DC bus 122.

At sub-block 4042, the electrical power transferred from the onboardenergy storage device and the external power source are combined. In oneembodiment, the electrical power provided from the onboard energystorage device 102 and the electrical power provided from the onboardpower interface or the onboard power conversion device 196 is combinedat the DC bus 122.

At sub-block 4044, at least one electrical connection between the DC busand a drive system is established. In one embodiment, a first energytransfer link between the DC bus 122 and the TM branch 124 isestablished. The establishment of the first energy transfer link may beachieved by transmitting a switching signal 164 from the vehiclecontroller 152 to a TM switch 108, so that the TM switch 108 can beturned on or closed according to the switching signal 164. In anotherembodiment, a second energy transfer link between the DC bus 122 and thePTO branch 126 can be established. The establishment of the secondenergy transfer link can be achieved by turning on or closing the PTOswitch 138 according to switching signal 162 transmitted from thevehicle controller 152.

At sub-block 4046, the process continues to implement by transferringelectrical power through the established energy transfer link. In oneembodiment, when the first energy link between the DC bus 122 and the TMbranch 124 is established, DC electrical power at the DC bus 122 can beprovided to TM inverter 114 in the TM branch 124. The TM inverter 114converts the received DC electrical power to AC electrical power 116which is used by the traction motor 118 to provide mechanical outputsuch as torque output for driving motion of the vehicle 180. In anotherembodiment, when the second energy transfer link between the DC bus 122and the PTO branch 126 in established, DC electrical power at the DC bus122 can be transferred to the PTO inverter 144 in the PTO branch 126.The PTO inverter 144 converts the received DC electrical power to ACelectrical power 146 which is used by the PTO motor to providemechanical outputs such as torques outputs to perform one or morespecific tasks in association with the vehicle 180.

Referring now to FIG. 12, the method 5000 generally provides a combinedcharging and operation control mode for the vehicle 180 to implement oroperate with. The method 5000 contains similar blocks as those have beendescribed with reference to FIGS. 9-10. For example, the method 5000contains a block 5002 which is similar to blocks 3002, 4002 describedabove for establishing an electrical connection between the vehicle andan external power source.

At block 5004, following the established electrical connection betweenthe vehicle and the external power source, electrical power from theexternal power source can be concurrently provided to the onboard energystorage device and at least a drive system of the vehicle. In oneembodiment, concurrently providing electrical power from the externalpower source to the onboard energy storage device and at least one drivesystem may involve a plurality of actions to be performed. FIG. 13illustrates various actions that may be involved in block 5004 inaccordance with one exemplary embodiment of the present disclosure.

Referring to FIG. 13, at sub-block 5022, electrical power obtained fromthe external power source is converted into a suitable form. In oneembodiment, as shown in FIG. 8, the onboard power conversion device 196converts the electrical power (e.g., AC electrical power from a utilitypower grid) into DC electrical power for supply to the DC bus 122. Insome specific embodiments, the power conversion device 196 can becontrolled to operate at a constant output current mode. In the constantoutput current mode, the onboard power conversion device 196 suppliesthe DC electrical power with a constant current to the DC bus 122. Inone embodiment, a desired constant current value can be determined basedat least in part on the power that the traction motor 118 and/or the PTOmotor 148 desired to provide as well as the power that the battery orbatter pack of the onboard energy storage device 102 is desired to becharged with. After the desired current reference is determined, acommand signals representing the desired current reference can be inputto the vehicle controller 152, which in turn transmits control signals171 to cause the onboard power conversion device 196 to provide thedesired reference current output.

Further referring to FIG. 13, after sub-block 5022, the process isbasically split into two parallel branches 5030 and 5040. In the firstbranch 5030, at sub-block 5032, an energy transfer link between theonboard energy storage device and a DC bus is established. In oneembodiment, as shown in FIG. 8, the establishment of the energy transferlink between the onboard energy storage device 102 and the DC bus 122can be achieved by turning on or closing the ES switch 104 according toswitching signal 166 transmitted from the vehicle controller 152. Inalternative embodiment, the ES switch 104 may be turned on or closedmanually. At sub-block 5034, with the established energy transfer linkbetween the DC bus 122 and the onboard energy storage device 102, afirst part of electrical power at the DC bus 122 is transferred from theDC bus 122 to the onboard energy storage device 102.

Further referring to FIG. 13, at sub-block 5042 in the second branch5040, an energy transfer link between the DC bus and at least one drivesystem is established. In one embodiment, a first energy transfer linkbetween the DC bus 122 and the TM drive system or the TM branch 124 isestablished. More specifically, the establishment of the first energytransfer link between the DC bus 122 and the TM branch 124 can beestablished by turning on or closing the TM switch 108 according to theswitching signal 164 transmitted from the vehicle controller 152.Alternatively, the TM switch 108 can also be turned on or closedmanually. In another embodiment, a second energy transfer link betweenthe DC bus 122 and the PTO drive system or the PTO branch 126 isestablished. More specifically, the establishment of the second energytransfer link can be achieved by turning on or closing the PTO switch138 according to switching signal 162 transmitted from the vehiclecontroller 152. Alternatively, the PTO switch 138 can also be turned onor closed manually.

At sub-block 5044 of the second branch 5040, electrical power at the DCbus can be delivered through the established energy transfer link to theat least one drive system. In one embodiment, at least a second part ofDC electrical power at the DC bus 122 can be delivered through the firstenergy transfer link to the TM inverter 114 in the first branch 124. TheTM inverter 114 converts the DC electrical power to AC electrical powerfor driving the traction motor 118 to provide mechanical output such astorque output to drive motion of the vehicle 180. In another embodiment,at least a second part of DC electrical power at the DC bus 122 can bedelivered through the second energy transfer link to the PTO converter144 in the second branch 126. The PTO converter 144 converts DCelectrical power to AC electrical power for driving the PTO motor 148 toprovide mechanical output such as torque outputs to perform one or morespecific tasks in association with the vehicle 180.

Referring back to FIG. 12, at block 5006, the method 5000 continues todetermine whether an onboard energy storage device is fully charged. Thepurpose of this block 5006 is to ensure a battery or a battery pack ofthe onboard energy storage device will not be over-charged, because thebattery lifetime can be significantly reduced when the battery orbattery pack of the onboard energy storage device is over-charged. Inone embodiment, as shown in FIG. 8, a sensor 197 such as a currentdetector is used for detecting a charging current in association withthe battery or battery pack of the onboard energy storage device 102.The charging current feedback detected with the current detector 197 canbe supplied to the vehicle controller 152 for calculating or deducing acharging energy or a charging status of the battery or battery pack ofthe onboard energy storage device. Thus, determination can be made toascertain whether the battery or battery pack of the onboard energystorage device is fully charged by comparing the calculated chargingenergy or charging status with a predefined value. If the determinationreveals that the onboard energy storage device is fully charged, themethod 5000 may proceed to block 5008 or alternatively to block 5012 toimplement, which will be described in more detail later. If thedetermination reveals that the onboard energy storage device is notfully charged, the method 5000 may proceed to block 5014, which will bedescribed in more detail later.

At block 5008, following the determination at block 5006 that theonboard energy storage device has been fully charged, the onboard energystorage device may be disconnected from the external power source. Inone embodiment, the ES switch 104 is turned off or opened according toswitching signal 166 transmitted from the vehicle controller 152, suchthat the energy transfer link between the DC bus 122 and the onboardenergy storage device 102 is cut off. In alternative embodiment, the ESswitch 104 can be turned off or opened manually for cutting off theenergy transfer link. As shown with phantom line in FIG. 12, the block5008 may be omitted in some implementations. In this case, the method5000 may proceed to block 5012, particularly, electrical power from theexternal power source and the onboard energy storage device arecombined. In one embodiment, the combined electrical power may betransferred to at least one drive system such as the TM branch 124 andPTO branch 126 shown in FIG. 8. The operations involve in block 5014 issubstantially similar to the block 4014 shown and described above withreference to FIGS. 10-11, thus, detailed descriptions of the block 5012is omitted herein.

At block 5014, following the negative determination that the onboardenergy storage device is not fully charged, the method 5000 continues todetermine whether the onboard energy storage device is over-discharged.In one embodiment, the current detector 197 as shown in FIG. 8 can alsobe used to detect the direction of the current flowing through theenergy transfer link between the onboard energy storage device 102 andthe DC bus 122. More specifically, when the current is detected beingflowing from the onboard energy storage device 102 to the DC bus 122, itrepresents that the onboard energy storage device 102 is discharging.Further, the current feedback signals 199 can be transmitted to thevehicle controller 152 to further calculate or deduce a dischargingstatus of the onboard energy storage device 102. Thus, determination canbe made to ascertain whether the onboard energy storage device isover-discharged by comparing the discharging status with a predefinedvalue. If the determination reveals that the onboard energy storagedevice has been over-discharged, the method 5000 may proceed to block5016 to implement, which will be described in more detail later. If thedetermination reveals that the onboard energy storage device hasn't beenover-discharged, the method 5000 may return back to block 5004 forconcurrently providing electrical power from the external power sourceto the onboard energy storage device and at least one drive system. Inan alternative embodiment, following the negative determination at block5014, the method 5000 may return back to block 5012 to implement, tocombine the electrical power from the onboard energy storage device andthe external power source.

At block 5016, following the affirmative determination at block 5014that the onboard energy storage device is over-discharged, the method5000 continues to implement to disconnect the onboard energy storagedevice with the at least one drive system. It is also beneficial todetect whether a battery or battery pack of the onboard energy storagedevice is over-discharging, because an over-discharged battery orbattery pack also has a reduced battery lifetime. In one embodiment, thedisconnection is achieved by turning off or opening the ES switch 104according to the switching signal 166 transmitted from the vehiclecontroller 152, such that the energy transfer link between the DC bus122 and the onboard energy storage device 102 is cut off, thereby, theonboard energy storage device 102 cannot supply electrical power to theTM branch 124 and the PTO branch 126. Alternatively, the ES switch 104can be turned off or opened in a manual manner.

At block 5018, the method 5000 continues to implement by providingelectrical power from the external power source to at least one drivesystem. For example, as shown in FIG. 8, the electrical power from theexternal power source 12 can be converted by the onboard powerconversion device 196 to DC electrical power for supply to the DC bus122. In one embodiment, by turning on the TM switch 108, the electricalpower at the DC bus 122 can be supplied to the TM branch 124 for drivingmotion of the vehicle 180. In another embodiment, by turning on the PTOswitch 138, the electrical power at the DC bus 122 can be supplied tothe PTO branch 126 for performing one or more tasks in association withthe vehicle 180.

Although the embodiments discussed herein relate to the use withvehicles, aspects of the invention are not limited to that. Aspects ofthe invention may be used with other applications, such as elevators orescalators.

While the invention has been described with reference to exemplaryembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention.Furthermore, the skilled artisan will recognize the interchangeabilityof various features from different embodiments. Similarly, the variousmethod steps and features described, as well as other known equivalentsfor each such methods and feature, can be mixed and matched by one ofordinary skill in this art to construct additional assemblies andtechniques in accordance with principles of this disclosure. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the appendedclaims.

The written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to make and use the invention. The patentable scope of the inventionis defined by the claims, and may include other examples that occur tothose skilled in the art. Such other examples are intended to be withinthe scope of the claims if they have structural elements that do notdiffer from the literal language of the claims, or if they includeequivalent structural elements with insubstantial differences from theliteral languages of the claims.

What is claimed is:
 1. An apparatus comprising: an onboard energystorage device; an onboard power conversion device configured to beelectrically coupled to an external power source for receivingelectrical power therefrom; and at least one drive system electricallycoupled to the onboard energy storage device and the onboard powerconversion device, wherein the onboard energy storage device and theonboard power conversion device cooperatively provide electrical powerfor the at least one drive system.
 2. The apparatus of claim 1, whereinthe at least one drive system comprises a traction drive system and apower take-off (PTO) drive system, the traction drive system isconfigured to receive electrical power cooperatively provided from theonboard energy storage device and the onboard power conversion devicefor driving movement of the apparatus, and the PTO drive system isconfigured to receive electrical power cooperatively provided from theonboard energy storage device and the onboard power conversion devicefor driving movement of at least one implement in association with thePTO drive system.
 3. The apparatus of claim 2, wherein the apparatuscomprises an electric tractor, and the at least one implement comprisesat least one of a plow, a forklift, a dump, a shovel, and an excavator.4. The apparatus of claim 1, wherein the external power source comprisesat least one of a utility power grid, a portable electricity generator,a wind turbine generator, hydro-micro turbine generator, and a solarpanel.
 5. The apparatus of claim 1, further comprising: a direct-current(DC) bus coupled to the onboard energy storage device and the onboardpower conversion device; and an energy storage switch electricallycoupled to the onboard energy storage device and the DC bus, whereinwhen the apparatus is operating in a charging mode, the energy storageswitch is closed to allow at least a part of the electrical powerprovided from the onboard power conversion device to be transferred tothe onboard energy storage device via the DC bus and the energy storageswitch.
 6. The apparatus of claim 5, wherein when the apparatus isoperating in a driving mode, the energy storage switch is opened to stopcharging the onboard energy storage device.
 7. The apparatus of claim 6,further comprising: a vehicle controller electrically coupled to theenergy storage switch, wherein the vehicle controller is configured tosend a first switch signal to close the energy storage switch when theapparatus is operating in the charging mode; and the vehicle controlleris further configured to send a second switch signal to open the energystorage switch when the apparatus is operating in the driving mode. 8.The apparatus of claim 5, wherein when the apparatus is operating in thecharging mode, the at least one drive system is disabled.
 9. Theapparatus of claim 2, further comprising: a DC bus coupled to theonboard energy storage device and the onboard power conversion device;and a traction switch electrically coupled to the DC bus and thetraction drive system wherein when the apparatus is operating in acharging mode, the traction switch is opened to disable the tractiondrive system, and wherein when the apparatus is operating in a drivingmode, the traction switch is closed to allow at least a part of theelectrical power provided from the onboard power conversion device to betransferred to the traction drive system via the DC bus and the tractionswitch.
 10. The apparatus of claim 2, further comprising: a DC buscoupled to the onboard energy storage device and the onboard powerconversion device; and a PTO switch electrically coupled to the DC busand the PTO drive system, wherein when the apparatus is operating in acharging mode, the PTO switch is opened to disable the PTO drive system,and wherein when the apparatus is operating in a driving mode, the PTOswitch is closed to allow at least a part of the electrical powerprovided from the onboard power conversion device to be transferred tothe PTO drive system via the DC bus and the PTO switch.
 11. Theapparatus of claim 1, wherein when a state of charge (SOC) of theonboard energy storage device is determined to be below a low-SOCthreshold value, an energy transfer link is established between theonboard power conversion device and the onboard energy storage device,such that at least a part of the electrical power provided from theonboard power conversion device is transferred along the energy transferlink to the onboard energy storage device.
 12. The apparatus of claim 1,wherein when a SOC of the onboard energy storage device is determined tobe above a high-SOC threshold value, the at least one drive system isdriven by a combination electrical power provided from the onboardenergy storage device and the onboard power conversion device.
 13. Theapparatus of claim 1, wherein during the time period that at least apart of the electrical power provided from the onboard power conversiondevice is delivered to at least one drive system, at least another partof the electrical power provided from the onboard power conversiondevice is delivered to charge the onboard energy storage device.
 14. Theapparatus of claim 1, further comprising: an energy storage switchelectrically coupled to the onboard energy storage device; a sensorcoupled to an output of the onboard energy storage device; and a vehiclecontroller coupled in electrical communication with the energy storageswitch and the sensor; wherein when a sensor feedback signal generatedfrom the sensor and transmitted to the vehicle controller indicates thatthe onboard energy storage device is over-charged or over-discharged,the vehicle controller sends a control signal to open the energy storageswitch.
 15. A vehicle, comprising: an onboard energy storage device forproviding a first direct current (DC) power; an alternatingcurrent-direct current (AC-DC) converter configured to be electricallycoupled to a utility power grid for receiving input alternating current(AC) power from the utility power grid and converting the input AC powerto provide a second DC power; a DC bus electrically coupled to theonboard energy storage device and the AC-DC converter for receiving thefirst DC power and the second DC power respectively; a traction inverterelectrically coupled to the DC bus for converting at least one of thefirst DC power and the second DC power received at the DC bus totraction AC power; and a traction motor electrically coupled to thetraction inverter, the traction motor configured to convert the fractionAC power received from the traction inverter to mechanical power todrive movement of the vehicle, wherein the AC-DC converter continuesreceiving the input AC power from the utility power grid to maintain themovement of the vehicle.
 16. The vehicle of claim 15, furthercomprising: a power take-off (PTO) inverter electrically coupled to theDC bus for converting at least one of the first DC power and the secondDC power received at the DC bus to PTO AC power; and a PTO motorelectrically coupled to the PTO inverter, the PTO motor configured toconvert the PTO AC power received from the PTO inverter to mechanicalpower to drive movement of at least one PTO implement in associationwith the PTO motor, wherein the AC-DC converter continues receiving theinput AC power from the utility power grid to maintain the movement ofthe at least one PTO implement.
 17. The vehicle of claim 16, whereinsimultaneously with at least a part of the second DC power beingdelivered to at least one of the traction inverter and the PTO inverter,at least another part of the second DC power is transferred to chargethe onboard energy storage device.
 18. A method of managing power supplyof an apparatus, comprising: receiving input alternating current (AC)power from a utility power grid; converting the received input AC powerto provide a first DC power; and converting at least part of the firstDC power to at least one of a traction AC power and a power take-off(PTO) AC power, respectively, for a traction motor and a PTO motor ofthe apparatus, wherein receiving input AC power from a utility powergrid is implemented concurrently with converting at least part of thefirst DC power to at least one of a traction AC power and a PTO ACpower.
 19. The method of claim 18, further comprising transferring atleast part of the first DC power to an energy storage device of theapparatus.
 20. The method of claim 19, wherein the transferring at leastpart of the first DC power to an energy storage device of the apparatusis implemented concurrently with converting the DC power to at least oneof a traction AC power and a PTO AC power.
 21. The method of claim 18,further comprising: receiving a second DC power provided from an onboardenergy storage device; and converting a combination of the first DCpower and the second DC power to at least one of the traction AC powerand the PTO AC power.
 22. The method of claim 18, further comprising:determining whether an onboard energy storage device of the vehicle isover-charged or over-discharged; and discontinuing an energy transferbetween the utility power grid and the onboard energy storage device inresponse to the determining that the onboard energy storage device isover-charged or over-discharged.